Currently, in the distribution and logistics industry, the number of packages to be handled tends to increase. In recent years, however, there has been a concern that the declining birthrate and aging population invites a labor shortage. Logistic companies are therefore dealing with automation of a logistic system.
The conveyance and storage of packages in warehouses become increasingly automated using conveyor belts. On the other hand, the transfer operation of transferring packages to another place, such as unloading and picking, is difficult to automate and needs some contrivance.
As a device that automates the above transfer operation, a vacuum device is known in which a suction pad is brought into contact with the top of a package to vacuum the package, and raise and move it to a desired place.
However, when the top of a package is inclined with respect to the horizontal plane due to a load shift or when the top of a package itself is bent, it is difficult to vacuum a suction pad onto the top of the package.
Furthermore, for example, when it is considered that a plurality of vacuum devices are arranged in parallel with a hand to vacuum and support a plurality of packages at once, if the packages are different in size, their tops are also different in height, thus making it difficult to vacuum all of the packages at once.
It is therefore desired to develop a vacuum device capable of vacuuming a suction pad onto a to-be-vacuumed surface of a vacuum target with reliability and an article holding device capable of vacuuming a plurality of vacuum target of different sizes at the same time.